Device for stopping the revolutions of the drum in elevating machinery



modem .G; DRYDEN. DEVIGBI'OR STOPPING THE REVOLUTION OF THE DRUM IN ELEVATING 2 Sheets-Sheet 2.

MACHINERY.

No. 252,085. Patented Jan.' 10,'1882.

f name STATES PATENT OFFice,

GEORGE DRYDEN, OF BOSTON, MASSACHUSETTS.

DEVICEFORSTOPPING THE REVOLUT IONS OF THE DRUM IN ELEVATING MACHINERY.

SPECIFICATION forming part of Letters Patent No, 252,085, dated January 10, 1882.

A Application filedOctober 17,1881. (No model.)

To all whom itmay concern:

Be it known that I, GEORGE DRYDEN, of Boston, in the county of Suffolk and State of Massachusetts, have invented a new and use ful improved device to be applied to machinery for running elevators, which operates when an elevator is hungup by the application.of an y of the various devices in use upon elevatorcars to stop a car when falling, or whenever a car is hung up from any cause proceeding from the car itself, or from the cable by which it is held, to stop the revolution of the drum, and thus prevent the cable holding the car from becoming entangled in the machinery.

The accompanying drawings, which form a part of this specification, fully illustrate my invention and its. application to elevating machinery. Figure 1 thereof is a side elevation in part section; Fig. 2 is an end elevation; and Fig. 3 is a diagram for the illustration of my auxiliary drum with weight attached. Fig. 4 illustrates in perspective the exact application of my invention in its relations to the elevator itself, to the drum, and to thelifting-cable, showing the elevator with the lifting-cable passing from the elevator up over the pulleys in the upper part of the building, and then down and over the drum in the basement, in the usual and well-known manner.

Like letters of reference designate like parts in the difi'erent figures.

My invention consists in placing the wormgear, which has heretofore been made fast upon the drum-shaft, loose upon said shaft, then a ratchet-gear is attached to the drum, over which drum the cable holding the car runs, or, rather, the ratchet-gear is attached directly 'to the auxiliary drum for holding a brake-cord, which auxiliary drum is attached to the main drum. Asufficient number (preferably three) of pawls are attached to said loose worm-gear, said pawls bearing upon said ratchet-gear, all operating to stop the movement of said main drum when the car is hung up, and thereby prevent the cable holding the car and wound around said main drum from becoming entangledin the machinery. The weight attached to said brake-cord operates to counteract the momentumof the drum, and thus secure a sudden stop of said drum afterthe cable slackens, and

the weight also serves as an aid to the revolution ofthe drum when the elevator is on its upward course, allot which is hereinafterfnlly described.

A is adrum, over which the cable B, which holds the elevator-car, is carried, said. drum A being faston thedrum-shaft D. Theauxi'iary drum a is held fast to the main drum A by means ofthe spurs e, bolted to said main drunk], as shown in Fig. 1, or by other equivalent means. The brake-cord h passes over the periphery of the auxiliary drum a, then over the two pulleys j, and at'the end of said cord h is attached the weight It. The ratchet-gear b is made fast to the side of the auxiliary drum a, so that said ratchet-gear moves with the drum A. The worm-gear g is loose upon the drumshaft d, as before stated, and attached to the side of said worm gear are the pawls c, preferably three in number, as shown. The wormshat'tpasses under said worm gear 9 at the pointf, as shown in Fig. 1, the worm of said worm -shaft meshinginto and carrying said loose worm-gear g.

Having described the construction of m y device, and its application to elevating machinery, its operation may be described as follows When the car is moving upward the wormgear 9, and with it the drum A and the device attached thereto, is turning to the right, when looking at Fig. 2,1and when the car is moving downward said machinery is of course turning in the opposite direction, as indicated by the arrow in Fig. 2. When the elevator-car is going up and the worm-gear g is turning in the direction before indicated the pawls c, attached to said worm-gear, hold in the ratchets of the ratchet-gear b, as clearly shown in Fig. 2, and as said ratchet-gear is held fast to the auxiliary drum a, and said auxiliary drum is attached to the main drum A, said main drum of course turns in the same direction with said worm-gear, and the car being connected with the drum A by the cable B, the car moves upward, as above stated.

It is obvious that it is never necessary to hang a car up unless the car be falling. Now, when the car is moving downward in the usual and regular mannerthe weight of said car will of course carry the drum A, the speed being regulated by the pawls 0 bearing upon the ratchet-gear b, said pawls being attached to the worm-gear g. Upon the worm-shaft connecting with said worm-gear are placed the pulleys, over which pass the belts which connect said worm-shaft with the source of power. But when the car is hung up the cable B is thereby slackened, relieving the drum A of the weight of the car, and said drum therefore stops. The worm-gearg, beingloose upon the drum-shaft, continuesits revolutions, and the pawlsc, being attached to said worm-gear, move along over the ratchet gear without effect upon the drum, while in going up thepawls bear against the ratchets and thus turn the drum.

It is obvious that the momentum acquired by the drum A would keep it in motion certainly for a partot'a revolution after the slackening of the cable B, and to obviate this, and to render the stopping of the drum A more sudden, the cord h is carried around the auxiliary drum (0 and over the two 'pulleysj, and is provided with the weight h at its end, and as said auxiliary drum is attached to the main drum A it is obvious that the weight It will, when the car is hung up and the drum Ais relieved of the weight ot'said oar, act instantly as a brake and counteract the momentum above described. It will also be readily seen that when the car is running up the weight 7b acts asa counter-balance, and thereby aids the revolutions of the drum A.

Having fully described my invention and the mode ofcarrying the same into effect, what I claim as new, and desire to secure by Letters Patent, is-

1. In an elevating machine, the mode of stopping the revolving of the drum upon the elevator-car being hung up and thecableholding said car becoming loose, by means of a loose worm-gear upon the drum-shalt, with pawls attached to said worm-gear, said pawls operating in connection with a ratchet-gear, said ratchet-gear being attached to an auxiliary drum, saidauxiliary drum being made fast to the main drum and operating a brake, substantially as described.

2. In combination with an elevator-car, the drum A, the cable B, the drum shaft (1, the loose worm-gearg, with pawlsc attached thereto, the ratchet gear b, the auxiliary drum (4, with brakecord h, pulleys j,.and weight h, and the worm-shaft shown at the pointf, coristructed, and arranged substantially as described and shown, and for the purpose set forth.

GEORGE DRYDEN.

, Vitnesses:

CHARLES H. BARROWS, FRANCIS M. BOUTWELL. 

